I've had trouble trying to figure out the plot so far, but it finally dawned on me. Everything has been slowly driving Akuto to embrace his dark powers and his role as a demon lord. He keeps going further and further down the road.
- Yep. As of the end of Episode 9, he is fully on the path of his destiny.
It might explain why their culture seems to be a mixture of Japan and the West (even more so than modern-day Japan). Given the slight Byzantine motifs, it could have been Russia (taking advantage of Japan's weakness during the Warring States period as part of its eastward expansion). But instead of the racist genocide as seen in Code Geass, it was more of a puppet-state arrangement like Britain's domination of India. Feel free to elaborate.